On the neutron diffraction in crystals in the field of a standing sound wave

Abstract

The diffraction of neutrons is considered in crystals under the influence of a standing sound wave. The scattering probability is calculated for the elastic neutron–crystal interaction, whereas the neutron-standing sound wave interaction can be either elastic and inelastic. The possibility of short-wave (high-energy) neutrons diffraction is illustrated. It is shown that the Debye–Waller factor can be changed and tuned. The analysis of conservation laws are adduced both for thermal and short-wave neutrons. The formation of a “sublattice” is shown in the process of neutrons elastic diffraction with respect to standing sound wave. The analogous to the Kapitza–Dirac effect is considered for neutrons. The problem is solved within the frame of non-stationary S-matrix theory, where the neutron–phonon interaction is described by the Fermi pseudopotential, which is considered as a perturbation.